Recent results from hadron colliders

This is a summary of some of the many recent results from the CERN and Fermilab colliders, presented for an audience of nuclear, medium-energy, and elementary particle physicists. The topics are jets and QCD at very high energies, precision measurements of electroweak parameters, the remarkably heavy top quark, and new results on the detection of the large flux of B mesons produced at these machines. A summary and some comments on the bright prospects for the future of hadron colliders conclude the talk. 39 refs., 44 figs., 3 tabs

Strategies for mimicking the primary events of bacterial photosynthesis: Structure, function, and mechanism

Some of the possible implications of the photochemistry of photosynthesis for artificial systems are presented. A major aspect of this paper involves the special conditions required to prevent the undesirable charge recombination via the excited triplet state of the primary donor. If a multi-jump model is operative in the primary events of photosynthesis, then artificial model systems are relatively easy to synthesize. Such systems prevent back reactions via a series of downhill chemical reactions. Each downhill step in energy results in an increase in charge separation distance. The annihilation reactions, even to the less energetic triplet state, involve intermediate states uphill in energy and consequently are greatly diminished. However, if superexchange is a correct explanation of photosynthesis, then model systems have not been developed that properly mimic the natural process. In particular, the triplet back reaction can occur due to the lack of any thermal activation barrier. In nature this downhill back reaction appears to be prevented by carefully balancing the energetics using four molecules in the electron transport system. If this is the case, artificial photosynthesis would also require fine tuning of the coupling and energetics with three or four molecules making duplication more difficult to achieve. 10 refs

The inflation sector of extended inflation

In extended inflation the inflationary era is brought to a close by the process of percolation of true vacuum bubbles produced in a first-order phase transition. In this paper I discuss several effects that might obtain if the Universe undergoes an inflationary first-order phase transition. 17 refs

The dilemma of fossil fuel use and global climate change

The use of fossil fuels and relationship to climate change is discussed. As the use of fossil fuels has grown, the problems of protecting the environment and human health and safety have also grown, providing a continuing challenge to technological and managerial innovation. Today that challenge is to control atmospheric emissions from combustion, particularly those emissions that cause acidic deposition, urban pollution, and increasing concentrations of greenhouse gases. Technology for reducing acidic deposition is available and needs only to be adopted, and the remedies for urban pollution are being developed and tested. How effective or expensive these will be remains to be determined. The control of emissions of the greenhouse gas, CO{sub 2}, seems possible only be reducing the total amounts of fossil fuels used worldwide, and by substituting efficient natural gas technologies for coal. Long before physical depletion forces the transition away from fossil fuels, it is at least plausible and even likely that the greenhouse effect will impose a show-stopping constraint. If such a transition were soon to be necessary, the costs would be very high because substitute energy sources are either limited or expensive or undesirable for other reasons. Furthermore, the costs would be unevenly felt and would be more oppressive for developing nations because they would be least able to pay and, on average, their use rates of fossil fuels are growing much faster than those of many industrialized countries. It is prudent, therefore, to try to manage the use of fossil fuels as if a greenhouse constraint is an important possibility

Gravitational couplings of the inflaton in extended inflation

We discuss a new extended inflationary scenario evading the difficulties of the original model. Our model can thermalize the energy in the bubble walls by the necessary epoch, and establish a Robertson-Walker frame in the bubble clusters. The essential new ingredient in our model is the observation that the coupling of inflaton to the Jordan-Brans-Dicke field is expected to be different from that of visible matter. 13 refs., 1 fig

Androgen receptor targets NFKB and TSPI to suppress prostate tumor growth in vivo

The androgen role in the maintenance of prostate epithelium is subject to conflicting opinions. While androgen ablation drives the regression of normal and cancerous prostate, testosterone may cause both proliferation and apoptosis. Several investigators note decreased proliferation and stronger response to chemotherapy of the prostate cancer cells stably expressing androgen receptor (AR), however no mechanistic explanation was offered. In this paper we demonstrate in vivo anti-tumor effect of the AR on prostate cancer growth and identify its molecular mediators. We analyzed the effect of AR on the tumorigenicity of prostate cancer cells. Unexpectedly, the AR-expressing cells formed tumors in male mice at a much lower rate than the AR-negative controls. Moreover, the AR-expressing tumors showed decreased vascularity and massive apoptosis. AR expression lowered the angiogenic potential of cancer cells, by increasing secretion of an anti-angiogenic protein, thrombospondin-1. AR activation caused a decrease in RelA, a subunit of the pro-survival transcription factor NF kappa B, reduced its nuclear localization and transcriptional activity. This, in turn, diminished the expression of its anti-apoptotic targets, Bcl-2 and IL-6. Increased apoptosis within AR-expressing tumors was likely due to the NF kappa B suppression, since it was restricted to the cells lacking nuclear (active) NF kappa B. Thus we for the first time identified combined decrease of NF kappa B and increased TSP1 as molecular events underlying the AR anti-tumor activity in vivo. Our data indicate that intermittent androgen ablation is preferable to continuous withdrawal, a standard treatment for early-stage prostate cancer. (C) 2007 Wiley-Liss, Inc.The androgen role in the maintenance of prostate epithelium is subject to conflicting opinions. While androgen ablation drives the regression of normal and cancerous prostate, testosterone may cause both proliferation and apoptosis. Several investigators note decreased proliferation and stronger response to chemotherapy of the prostate cancer cells stably expressing androgen receptor (AR), however no mechanistic explanation was offered. In this paper we demonstrate in vivo anti-tumor effect of the AR on prostate cancer growth and identify its molecular mediators. We analyzed the effect of AR on the tumorigenicity of prostate cancer cells. Unexpectedly, the AR-expressing cells formed tumors in male mice at a much lower rate than the AR-negative controls. Moreover, the AR-expressing tumors showed decreased vascularity and massive apoptosis. AR expression lowered the angiogenic potential of cancer cells, by increasing secretion of an anti-angiogenic protein, thrombospondin-1. AR activation caused a decrease in RelA, a subunit of the pro-survival transcription factor NF kappa B, reduced its nuclear localization and transcriptional activity. This, in turn, diminished the expression of its anti-apoptotic targets, Bcl-2 and IL-6. Increased apoptosis within AR-expressing tumors was likely due to the NF kappa B suppression, since it was restricted to the cells lacking nuclear (active) NF kappa B. Thus we for the first time identified combined decrease of NF kappa B and increased TSP1 as molecular events underlying the AR anti-tumor activity in vivo. Our data indicate that intermittent androgen ablation is preferable to continuous withdrawal, a standard treatment for early-stage prostate cancer. (C) 2007 Wiley-Liss, Inc